Rassolnik Tom Yum

Hello! Me (Russian) and my partner (US citizen) have been on the process of collecting everything needed for filing the I-129F petition. Since I come from a not English-speaking country, I got confused regarding translations of our proofs. I would be really happy to know your advice or experience on following: 1. Since I've been adopted as a child of 8 y.o. I need to attach the proof of Legal Name Change, am I right? I don't use the surname I had before being adopted, but I listed it in the petition form just in case cause I'm used to do it in this kind of questions when I do paperwork for Russian legal affairs. My certificate of the adoption is in my native language. Should I hire a third party translator to legally translate it into English? I should not translate it myself since I'm not a professional, should I? If so, what are the requirements for the translator to hire? 2. We also need to provide the proof of having met in past two years and ongoing relationships. Since we gathered all proofs in one place, we realized a lot of our proofs have some parts either in Russian (since my fiancé travelled to Russia to see me and used my native language in his postcards and stuff) and in Thai (since we both travelled to this country a lot to meet up). Does this mean that we also should hire third party translators to legally translate it all into English? If so, should each and every foreign word be translated? Or only those parts that make the most sense and meaning? Thank you so much for your help to solve our confusion!